The process of converting the analog sample into discrete form is called ______.
sampling
| Concept | Description |
|---|---|
| Analog Signal | A signal that varies continuously in both time and amplitude. |
| Discrete-Time Signal | A signal defined only at specific points in time (samples), but whose amplitude can still be continuous. |
| Discrete-Amplitude Signal | A signal whose amplitude can only take on a finite set of values, but which may be continuous or discrete in time. |
| Digital Signal | A signal that is discrete in both time and amplitude. |
Understanding Analog to Discrete Conversion
Converting an analog signal, which is continuous in both time and amplitude, into a digital signal requires a few steps. The first step involves making the signal discrete in time. This is achieved by taking samples of the signal at regular intervals.
The question asks about the process of converting an "analog sample into discrete form". While the phrasing might be interpreted in different ways, based on the provided options, it points towards a fundamental process in signal processing.
What is Sampling?
Sampling is the process of converting a continuous-time analog signal into a discrete-time analog signal. This is done by taking measurements (samples) of the analog signal's amplitude at specific, typically equally spaced, points in time. The result is a sequence of analog values, where each value corresponds to the signal's amplitude at a particular sample instant. Even though we have samples at discrete time points, the amplitude of these samples can still vary continuously, meaning they are still analog in value.
If the question implies converting the continuous-time analog signal into a sequence of discrete-time analog samples, then sampling is the correct term.
Why Other Options Are Not the Correct Process
- Modulation: Modulation is the process of varying one or more properties of a periodic waveform (the carrier wave) with a modulation signal that typically contains information to be transmitted. It is used in communication systems, not for converting a signal into discrete form in this context.
- Demultiplexing: Demultiplexing is the process of separating a single stream of multiplexed signals back into its constituent individual signals. This is related to transmitting multiple signals over a single channel, not to converting an analog signal into a discrete form.
- Quantization: Quantization is the process of mapping continuous analog amplitude values (or a wide range of discrete analog values) into a finite set of discrete digital values (amplitude levels). It is the process that converts an analog sample (which has a continuous amplitude) into a discrete amplitude value. While this aligns closely with "converting the analog sample into discrete form" (referring to discrete amplitude), the term provided as the correct answer is "sampling". Quantization is typically performed *after* sampling in the Analog-to-Digital Conversion (ADC) process.
Considering the common stages of Analog-to-Digital Conversion (ADC) and the provided answer, the question is likely referring to the initial step where the signal becomes discrete in time, even if the samples remain analog in amplitude initially. This initial step is sampling.
Conclusion
Based on the standard terminology in signal processing and the options provided, the process of converting the analog signal into discrete-time points (samples) is called sampling. While converting the amplitude of these samples into discrete values is called quantization, the question's phrasing, coupled with the provided answer, suggests it refers to the sampling step where the signal takes a "discrete form" in the time domain.
Revision Table: Signal Conversion Steps
| Process | Input | Output | Makes Signal Discrete In |
|---|---|---|---|
| Sampling | Continuous-Time Analog Signal | Discrete-Time Analog Signal (sequence of samples) | Time |
| Quantization | Analog Samples (or Continuous Amplitude) | Discrete-Amplitude Values (quantized levels) | Amplitude |
| Encoding | Quantized Values | Binary Code (digital representation) | Representation |
Additional Information: Analog-to-Digital Conversion
The complete process of converting a continuous-time analog signal into a digital signal typically involves three main steps:
- Sampling: The analog signal is sampled at regular intervals to obtain a discrete-time analog signal. The rate at which samples are taken is called the sampling rate or sampling frequency.
- Quantization: The amplitude of each analog sample is converted into one of a finite number of discrete amplitude levels. This process introduces quantization error.
- Encoding: Each discrete amplitude level is represented by a unique digital code, typically a binary number. This results in a digital signal, which is discrete in both time and amplitude.
These steps transform the analog signal into a digital format suitable for digital processing, storage, or transmission. The quality of the digital representation depends on the sampling rate (Nyquist-Shannon theorem) and the number of quantization levels (bit depth).
Important Questions from Sampling
Respondents of a recent sample survey provided names of friends they thought would be likely users of a new product. These friends were contacted, completed a survey, and asked to supply names of other likely users. Which method of sampling has been used in this survey ?
Which one among the following relates to the probability-based sampling technique?
In which process is the flat-top pulse amplitude modulated signal generated?
Consider a population of 3 units having values 2, 4 and 6. A simple random sample (without replacement) of 2 units is to be drawn from the population. Let M denote the sample mean of this sample. Then which of the following statements are true?
Let x(t) be a signal with Nyquist rate ω 0. Determine the Nyquist rate for y(t) = x(t)cos(ω 0t)
